JP2001032520A - Positioning device for extensible ladder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positioning device for an extensible ladder which can be easily manufactured and by which a positioning work can be easily and securely carried out when the length of the extensible ladder is adjusted to position the ladder. SOLUTION: This device is formed of a support body 11 of the ladder and an extensible support 14 slidably fitted. An engaging projection 24 is circularly protruded at the external end face of the engaging body 19 and formed to engage with a plurality of round holes 25 as engaging holes formed in the extensible support 14. The round holes 25 of the extensible support 14 are formed at every constant distance by a press working. The engaging projection 24 is formed by protrusively drawing out the end face of the engaging body 19. The engaging body 19 is formed rectactably from a housing frame 20 by a fixing member and the engaging projection 24 is engaged with the round hole 25 of the extensible support 14 or disengaged from it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telescopic ladder positioning device for using a telescopic ladder at a place where scaffolds have different heights.

[0002]

2. Description of the Related Art As a conventional ladder of this type, for example, a ladder having a configuration as disclosed in Japanese Patent Application Laid-Open No. 11-22351 is known.

[0003] In this conventional configuration, the telescopic ladder positioning device is formed of a column main body of the ladder and a telescopic column slidably mounted on the column main body.
The fixing mechanism is attached and fixed to the column body. The engaging body constituting the fixing mechanism is housed in a housing frame fixed in the housing case so as to be able to advance and retreat. The rotation plates are arranged on both sides of the engagement body, and are rotatably supported by a support shaft fixed to the storage case. The operating pin is supported at the center of the engagement body,
Both ends are engaged with arc-shaped long holes provided at the tip of the rotating plate. The operation pin is guided to the elongated hole by the rotation of the rotation plate.

An engaging portion having an uneven shape is formed on an outer end surface of the engaging body, and can engage with an uneven surface of an uneven plate joined to a side surface of a telescopic strut. When adjusting the length of each column of the ladder, first, when a finger extended from the rotating plate is raised, the rotating plate is rotated about the support shaft. Thereby, the engagement between the engagement portion of the engagement body and the uneven surface of the expansion and contraction plate is released. Next, the telescopic strut is adjusted to an arbitrary length. Thereafter, the length is adjusted by operating the same finger hook to engage the engaging portion of the engaging body with the uneven surface of the expansion and contraction plate.

[0005] As another telescopic ladder, for example, a telescopic ladder having a configuration as disclosed in JP-A-11-93399 is known. In this conventional configuration, a plurality of locking holes are formed through the pillar body and the telescopic pillar.
The engaging body is expanded and contracted by the spring pressure of the rotating lever, and a columnar locking pin provided at the end thereof is formed to be able to advance and retreat with respect to the column main body and the telescopic column.

To adjust the length of each pillar of the ladder, when the rotating lever is rotated, the locking pin is pulled out from the overlapping locking hole of the pillar body and the telescopic pillar.
In this state, the telescopic strut is adjusted to an arbitrary length. After the adjustment, the turning lever is turned again, and the locking pin is penetrated so as to protrude from the overlapping locking hole of the column main body and the telescopic column, thereby fixing the position.

[0007]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open
In the conventional configuration disclosed in Japanese Patent Application Laid-Open No. 22351/1990, the engaging portion of the engaging body and the engaging surface of the telescopic strut are formed in an uneven shape, and are engaged by engaging the engaging portion and the engaging surface.
It is formed so that its position is fixed. For this reason, there is a problem in that if dust or the like adheres to the engaging portion or the engaging surface, the meshing becomes poor, the slip becomes easy, and it may not be possible to position completely.

On the other hand, in the conventional configuration disclosed in Japanese Patent Application Laid-Open No. 11-93399, a locking hole through which a locking pin is inserted is formed in the column main body and the telescopic column. For this reason, when manufacturing the support main body and the telescopic support, the work is not easy because the support main body and the telescopic support must be drilled so as to penetrate through a large number of locking holes. There was a problem that the manufacture of the positioning device became complicated.

The present invention has been made by paying attention to such problems existing in the prior art. It is an object of the present invention to provide a telescopic ladder positioning device that can easily and reliably perform the positioning operation when positioning by adjusting the length of the telescopic ladder, and that is easy to manufacture. .

[0010]

In order to achieve the above object, according to the first aspect of the present invention, a telescopic strut is slidably mounted on a strut main body of a ladder and engaged with the strut main body or telescopic strut. An engaging body having an engaging portion is housed in the support body fixed to the support body or the telescopic support so as to be able to advance and retreat with respect to the engaging hole, and the rotating member is turned around a support shaft fixed in the support body. It is movably supported, an arc-shaped long hole is formed in the rotating member or the engaging body so as to change the distance from the support shaft, and the rotating member or the engaging body advances and retreats by rotating the rotating member. An operating pin is provided so as to engage with the elongated hole, and a plurality of engaging holes are formed at regular intervals in the engaging surface of the column main body or the telescopic column, and the engaging body engages with the engaging hole. The joint projection is formed so as to be able to advance and retreat with respect to the column main body or the telescopic column.

According to a second aspect of the present invention, in the positioning device for the telescopic ladder according to the first aspect, the hole of the column main body or the telescopic column is formed by a press working method. According to a third aspect of the present invention, in the positioning device for a telescopic ladder according to the first or second aspect, the projecting engagement portion of the engagement body is formed by squeezing or caulking another member. It is.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 7, each of a pair of support bodies 11a and a support body 1 constituting a telescopic ladder.
The step plates 12 are respectively provided at fixed intervals between 1b. Each pair of support bodies 11a and support body 11
A support plate 13 is supported on b, and each of the column main bodies 11a and 11b is rotatable with respect to the support plate 13.

Similarly, each pair of support columns 11a and 11b has a pair of expandable columns 14 forming a telescopic ladder.
a and the telescopic strut 14b are slidably mounted, respectively.
The length of the telescopic ladder can be adjusted. And the grounds 15a, 15b, 15c, 15d having different heights
, Each pair of the support body 11a and the support body 11b
Are the corresponding telescopic struts 14a and telescopic struts 14b, respectively.
Is slid to a predetermined position, and each scaffold is placed so as to be stable. At the lower end of each telescopic strut 14,
A non-slip material 16 made of synthetic rubber is attached,
Each telescopic strut 14 is prevented from slipping on the ground 15a, 15b, 15c, 15d.

As shown in FIG. 1, a fixing mechanism 17 is attached and fixed to the lower end of each column body 11, and after the telescopic column 14 is positioned at a predetermined position with respect to the column main body 11, the telescopic column 14 is moved. It is designed to be fixed in position. Therefore, the fixing mechanism 17 will be described.

As shown in FIG. 1, FIG. 2 and FIG. 4, a rectangular box-shaped housing case 18 as a support is fixed to the lower end of the column main body 11 by welding. This storage case 1
The support body 8, the support body 11 and the telescopic support 14 are all made of aluminum.

As shown in FIG. 1, FIG. 2 and FIG.
The housing frame 20 is formed in a U-shape in cross section.
8 are fixed. The engaging body 19 is accommodated in the accommodating recess 21 of the accommodating frame 20 so as to be able to advance and retreat. The engaging body 19 is formed in a U-shape. At substantially center positions of both side walls thereof, mounting holes 23 for inserting and supporting the operating pin 22 are provided.
Is transparently provided. The engagement protrusion 24 is formed in a circular shape on the outer end surface of the engagement body 19, and is engageable with a round hole 25 as an engagement hole formed in a plurality of the extension columns 14.

The round holes 25 of the telescopic struts 14 are formed at regular intervals by a press working method. Further, the engagement protrusion 24 is formed by pressing the engagement body 19 from the inside and squeezing the engagement body 19 into a protrusion shape, and then pressing the engagement body 19 from the outside so as to reduce the roundness of the corner of the engagement protrusion 24. Have been. The support shaft 26 is inserted into the insertion hole 27 of the housing frame 20, and both ends thereof are fixed to the housing case 18. The support shaft 26 is disposed on a line extending through the operating pin 22 in the moving direction of the engagement body 19.
Fixed on top.

As shown in FIGS. 5 (a) and 5 (b), a rotary plate 28 as a plate is formed in a fan shape from aluminum, and the support shaft 26 is inserted into a support hole 29 provided on one side thereof. Can be rotated around the center. An arc-shaped long hole 30 is formed on the tip side of the rotating plate 28.
The long hole 30 is formed such that the distance from the support hole 29 is the shortest distance L1 at one end and the longest distance L2 at the other end. The operating pin 22 is inserted into the slot 30.
Are engaged, and the operation pin 22 is guided by the long hole 30 and moves by the rotation of the rotation plate 28.

As shown in FIGS. 1, 3 and 4, an operating plate 31 is joined to the end surfaces of the pair of rotating plates 28 in a state of being opposed to each other. The finger hook 33 is formed by cutting out the lower end surface of the operation plate 31 in an arc shape. The spring hooks 34 are formed so as to protrude from the outer surfaces of the rotary plates 28. A pair of winding springs 35 is wound around both ends of the support shaft 26, and one end is attached to a spring hook 34 and the other end is attached to the housing case 18. This winding spring 35
Is biased so as to hold the rotating plate 28 in the state shown in FIG. 1, that is, to rotate the rotating plate 28 clockwise. The engagement projection 24 of the engagement body 19 is always engaged with the round hole 25 of the telescopic strut 14.

In this state, the operation pin 22 is moved along the elongated hole 30 by putting a finger on the finger hook 33 of the operation plate 31 and rotating the rotation plate 28 against the urging force of the winding spring 35. The engaging body 19 is moved backward. Then, the engagement of the engagement projection 24 of the engagement body 19 with the round hole 25 of the telescopic strut 14 is released, and the telescopic strut 14 can be slid to an arbitrary position with respect to the engaging portion. The pair of rotating plates 28, the operation plate 31, the long holes 30, the support holes 2
The rotation member 32 is constituted by 9 and the like.

Next, the operation of the telescopic ladder positioning device of this embodiment will be described. As shown in FIG. 7, the telescopic ladders are grounded at different heights 15a, 15b, 15c, 15
d, the pair of telescopic struts 14a and telescopic struts 14b corresponding to the respective pairs are slid to predetermined positions,
It is necessary to place each scaffold stably.

For this reason, as shown in FIGS. 2 and 5 (a) and 5 (b), the operating plate 31 joined to the end face of the rotating plate 28
2 and pulls it to the right in FIG. 2 against the urging force of the winding spring 35 to rotate the rotating plate 28 about the support shaft 26 in the counterclockwise direction in FIG. The operation pin 22 is guided by the long hole 30 and moves by the rotation of the rotation plate 28. At this time, the distance between the elongated hole 30 and the support shaft 26 is determined by the longest distance L2 between the one end where the operating pin 22 was engaged before the rotation of the rotation plate 28 and the support shaft 26, and the rotation plate 28 Is changed to the shortest distance L1 between the other end where the operating pin 22 engages and the support shaft 26.

Accordingly, the distance between the support shaft 26 and the elongated hole 30 is reduced, and the engaging member 19 retreats in the housing frame 20. At this time, the moving distance of the engagement body 19 depends on the longest distance L2 between one end where the operation pin 22 was engaged before the rotation of the rotation plate 28 and the support shaft 26 and the operation pin 22 after the rotation. This is the difference in the shortest distance L1 between the other end and the support shaft 26. As a result, the engagement protrusion 24 of the engagement body 19 is separated from the round hole 25 of the telescopic strut 14. In this state, the telescopic strut 14 is slid with respect to the strut body 11 to a predetermined position.

Next, as shown in FIG.
The pivot plate 28 is pulled clockwise around the support shaft 26 by the biasing force of the winding spring 35, and returns to the original state. As a result, the operating pin 22 is guided by the long hole 30 and moves to the left in the figure. That is, the engaging body 19 moves in the advance direction again, the engaging projection 24 engages with the round hole 25 of the telescopic strut 14, and the telescopic strut 14 and the strut main body 11 are fixed at a predetermined position.

In this manner, the telescopic struts 14 are positioned and fixed at predetermined positions with respect to the strut body 11, respectively, and the telescopic ladders have different heights of the grounds 15a, 15b, 15b.
It is arranged in a stable state on c and 15d.

The effects exerted by the above embodiment will be described below. In the positioning device of the telescopic ladder of this embodiment,
A plurality of engaging projections 24 are formed in the round hole 2
5 is engaged and held by being inserted into the telescopic strut 5, the engagement is easy, and a high engaging force is exhibited, so that the telescopic strut 14 can be reliably fixed at a desired position.

In the telescopic ladder of this embodiment, the round hole 25 as the engaging hole of the telescopic strut 14 is
Are formed in a circular shape at regular intervals on one side surface by a press working method. For this reason, the drilling process is easy, and the manufacture of the telescopic ladder is easy.

In the positioning device for the telescopic ladder of this embodiment, the engaging projection 24 of the engaging body 19 is formed by being projected by squeezing, and then further pressed from the outer surface. For this reason, the roundness of the corner of the engagement protrusion 24 is reduced, and the detachment of the engagement portion due to a shift or the like is suppressed.

In the positioning device of the telescopic ladder according to this embodiment, when the operation plate 31 is pulled or separated by a finger, the rotation plate 28 rotates about the support shaft 26 and The engaged operating pin 22 is guided by the elongated hole 30 and moves. In this manner, since the engaging body 19 advances and retreats, the engaging body 19 can be easily advanced and retracted only by an operation of pulling or releasing the operating plate 31 with a finger. Therefore, the conventional screw is not required, and the telescopic ladder can be easily positioned and fixed at a predetermined position.

The above-described embodiment can be modified and embodied as follows. As shown in FIGS. 6B and 6C, after the separate T-shaped engagement protrusion 24 is inserted into the insertion hole 36 of the engagement body 19,
By crimping the engagement protrusion 24, the engagement protrusion 24 is integrated with the engagement body 19.

With this configuration, the engaging body 19 having a small rounded corner of the engaging projection 24 can be reliably manufactured, and the detachment of the engaging portion due to a shift or the like can be suppressed. A fixing mechanism 17 is provided on the telescopic strut 14 and its engaging body 19
To form an engaging projection 24 and a plurality of round holes 25 in the support body 11.

Even with such a configuration, the engagement protrusion 24 is
Since the engagement is maintained by being inserted into a plurality of round holes 25 formed in the column main body 11, the engagement is easy, and a high engagement force is exerted, so that the telescopic column 14 is securely placed at a desired position. Can be fixed to

The engaging projection 24 of the engaging body 19 and the telescopic strut 1
Four round holes 25 are formed so as to correspond to each other in a square shape. Even in this case, similarly, a high engaging force is exerted, and the telescopic strut 14 can be reliably fixed at a desired position.

The engaging body 19 and the engaging projection 24 are formed in an integral rod shape. In this case, the structure is simplified, and the drawing process is not required, and the manufacturing cost can be further reduced.

Next, the technical idea grasped from the above embodiment will be described below. The positioning device for a telescopic ladder according to any one of claims 1 to 3, wherein the engagement hole of the telescopic strut is formed only on one side surface of the telescopic strut.

With this configuration, it is not necessary to form engagement holes on a plurality of surfaces, so that the manufacturing process can be simplified and the manufacturing cost can be reduced. The positioning device for a telescopic ladder according to any one of claims 1 to 3, wherein the center of the engagement protrusion is formed on an extension of the moving direction of the operating pin.

When formed in this manner, engagement and disengagement of the engagement projections with the engagement holes becomes smooth. The positioning device for a telescopic ladder according to claim 1, wherein the fixing mechanism is formed at a lower end of the column main body.

When formed as described above, the telescopic strut can be extended more effectively.

[0039]

The present invention is configured as described above, and has the following effects. According to the positioning device of the telescopic ladder of the first aspect, when positioning by adjusting the length of the telescopic ladder, the positioning operation can be performed easily and reliably, and the production becomes easy.

According to the positioning device for a telescopic ladder according to the second aspect, in addition to the effects of the first aspect, drilling is facilitated, and the labor required for manufacturing can be reduced.

According to the positioning device for the telescopic ladder of the third aspect, in addition to the effects of the first or second aspect, the roundness of the corner of the engaging projection can be reduced, and Engagement of the engagement projection with the hole is further ensured.

[Brief description of the drawings]

FIG. 1 is a partial front sectional view showing a positioning device of a telescopic ladder in an engaged state.

FIG. 2 is a partial front sectional view showing a positioning device of a telescopic ladder in a disengaged state.

FIG. 3 is a plan sectional view showing a positioning device of the telescopic ladder.

FIG. 4 is a side view showing the storage case.

FIG. 5A is a cross-sectional view showing a rotating plate in an engaged state;
(B) is sectional drawing which shows the rotation board of an engagement release state.

6A is a perspective view showing an engagement body, FIG. 6B is an exploded sectional view showing an engagement protrusion formed separately from the engagement body,
(C) is sectional drawing which shows the state which crooked the engaging protrusion which consists of an engaging body at another.

FIG. 7 is a schematic perspective view showing a telescopic ladder on the ground.

[Explanation of symbols]

11 ... pillar main body, 14 ... telescopic pillar, 18 ... accommodation case as a support, 19 ... engagement body, 22 ... operating pin, 24 ...
Engagement projection, 25: round hole as engagement hole, 26: support shaft,
30: long hole, 32: rotating member.

Claims (3)

[Claims] 1. A telescopic strut is slidably mounted on a strut main body of a ladder, a plurality of engaging holes are formed in the telescopic strut or the strut main body at predetermined intervals, and are fixed to the strut main body or the telescopic strut. An engagement body having an engagement projection that engages with the engagement hole is accommodated in the support body, and the rotation member is rotatably supported by a support shaft fixed in the support body, and the rotation member or the engagement body The arc-shaped long hole is formed so as to change the distance from the support shaft, and the engaging body or the rotating member is moved forward and backward by the rotation of the rotating member, and the engaging projection is disengaged from the engaging hole. A positioning device for a telescopic ladder, wherein an operating pin to be engaged is provided to engage with the elongated hole. 2. An engaging hole of the telescopic strut or the strut body,
The positioning device for a telescopic ladder according to claim 1, wherein the positioning device is formed by a press working method. 3. The positioning device for a telescopic ladder according to claim 1, wherein the engagement protrusion of the engagement body is formed by squeezing or caulking another member.